Guide device for multivalve-actuating bridge for an internal combustion engine

ABSTRACT

In the valve mechanism for internal combustion engines, with each rocker arm actuating two or more valves through a bridge, a device for guiding the bridge comprising a flange rigidly fixed to a guide rod for guiding the bridge, said flange being mounted in a readily removable manner on the cylinder head and secured thereto by utilizing members of the valve mechanism.

United States Patent Inventor Atsushi Inoue Saitama-ken, Japan Appl. No.853,032 Filed Aug. 26, 1969 Patented Jan. 11, 1972 Assignee NissanDiesel Motor Co., Ltd.

Saitama-ken, Japan Priorities Sept. 18, 1968 Japan 43/80495;

Sept. 18, 1968, Japan, No. 43/804915 GUIDE DEVICE FORMULTIVALVE-ACTUATING BRIDGE FOR AN INTERNAL COMBUSTION ENGINE 2 Claims,9 Drawing Figs.

U.S.C1 123/90.22, l23/90.4, 123/90.67, 123/193 H Int. Cl F011 l/26 Fieldof Search 123/90, 188 SP, 188 GC, 90.39, 75 B, 193 H, 90.4, 90.22,

[ 5 6] References Cited UNlTED STATES PATENTS 1,434,188 10/1922123/90.22 1,528,568 3/1925 123/90.22 2,191,333 2/1940 l23/188X 2,385,95910/1945 123/90 3,400,693 9/1968 123/90 X FOREIGN PATENTS 1,165,3443/1964 Germany 123/90 L 250,129 4/1926 Great Britain 123/90 A 354,1168/1931 Great Britain.... 123/90 A 465,540 5/1937 Great Britain 123/90 APrimary Examiner-A1 Lawrence Smith Attorney-Beveridge & De GrandiABSTRACT: In the valve mechanism for internal combustion engines, witheach rocker arm actuating two or more valves through a bridge, a devicefor guiding the bridge comprising a flange rigidly fixed to a guide rodfor guiding the bridge, said flange being mounted in a readily removablemanner on the cylinder head and secured thereto by utilizing members ofthe valve mechanism.

PATENTED JAN? 1 I972 353355 SHEET 1 BF 4 FIG.1

Pmzmmm 1 m2 3,633,556

SHEET 2 [IF 4 PATENTEU MM 1 I972 3533556 SHEET 3 BF 4 ATSUSHI INOUEPATENTED JAN! 1 I972 SHEET 0F 4 FIG.9

3% (dye. f 7 QM GUIDE DEVICE FOR MULTIVALVE-ACTUATING BRIDGE FOR ANINTERNAL COMBUSTION ENGINE This invention relates to a valve mechanismfor an internal combustion engine of the type having a rocker armpivotally mounted on a rocker shaft, a cylinder head, a guide rodmounted on the cylinder head, a bridge having arms and slidably mountedon the guide rod so as to be urged by the movement of the rocker arm, aplurality of valves each stem of which is connected with respective armof the bridge, said stem being urged downwardly by the movement of thebridge and upwardly by a valve spring through a guide sleeve fixed toand passed through the cylinder head. More specifically the presentinvention concerns a guide device for guiding the upand-down movementofthe bridge in such a valve mechanism.

In the internal combustion engines of the type described herein, thevalve stem is connected with the arm of the bridge capable of moving upand down vertically along the guide rod, and the rocking motion of therocker arm is transmitted to said bridge to similarly move the valvestems in order to open and close the respective ports in the combustionchamber.

If the guide rod should be improperly positioned when assembling theengine or if loose motion should develop in the movement of the bridgeduring service, the valve stems would move erratically and thus wouldinterfere with the proper valve timing. It is therefore highly essentialthat the guide device is to be so designed as to prevent occurrence ofsuch erratic bridge movement and that utmost care should be exercised ininstalling the bridge guiding members.

The internal combustion engine construction is generally such that theguide rods must be mounted on the cylinder head. In conventional guidedevices, guide rods are either force or press fitted directly into thecylinder head or rigidly fitted to flanges and secured by welding,bolting or likewise jointing the flanges to the cylinder head.

Where the guide rod is designed for direct press fitting, the fitting ormating parts must be machined to much closer tolerances and thisrequirement calls for stricter dimensional control in manufacturing.Moreover, such a direct press fitted connection is liable, in the courseof service, to develop rattle and resultant water leakage because theconnection is subject to large stresses necessarily set up thereinduring operation. When a rattling condition has developed in the guidedevice, the cylinder head must be immediately be replaced or a secondarymechanical trouble may develop to damage the engine beyond repair. Ineither case, replacement of a guide rod that has worn down to the limitdue to sliding guide action entails a cumbersome and often complicatedprocedure.

In order to avoid the above-mentioned drawback of conventional guidedevices, I propose to hold down the flange, with which the guide rod isrigidly connected, to the cylinder head by manner that is basicallydifferent from the conventional manners, that is without using anexclusive means of securing the flange direct to the cylinder head.

According to a feature of this invention, a flange rigidly fixed to orintegrally formed with the lower end of the guide rod has holes forpassing the guide sleeve in which valve stem reciprocates guidedly and ashoulder is formed on the upper portion of the guide sleeve, said flangebeing rested on the cylinder head and fastened by the shoulders of theguide sleeves when the latter is fixed in place in the cylinder head.

According to a further feature of this invention, a flange rigidly fixedto or integrally formed with the lower end of the guide rod has holesfor passing the guide sleeve, said flange having annular boss aroundeach hole and being provided with a seat for the spring around the boss,and said flange being rested on the cylinder head and fastened theretoonly by the action of the valve spring. Therefore the action of thevalve spring is utilized to push down on the flange to hold it againstthe cylinder head.

Even where a flange according to this invention is used as a means ofsecuring the guide rod to the cylinder head, strict dimensional accuracyis no less required, and added caution has to be exercised, at the timeof securing the flange to the cylinder head, to preserve the originalshapes of various related parts. Furthermore, the guide device tosecured to the cylinder head is not free from the drawback mentionedabove.

To illustrate this invention in detail, attention is directed to theembodiments thereof shown in the attached drawings, in which:

FIG. 1 is a side view mainly in section of a portion of an internalcombustion engine according to an embodiment of this invention, showinga guide device as mounted in place;

FIG. 2 is a perspective view of a flange and a guide rod according tothe invention, having a recessed seat with a hole at each flange end;

FIG. 3 is a view similar to FIG. 2, showing a modification of theembodiment of FIG. 2;

FIG. 4 is a view similar to FIG. 2, showing another modification oftheembodiment of FIG. 2;

FIG. 5 is a side view in section, exemplifying a manner of securing tothe cylinder head the flange shown in FIGS. 3 or 4;

FIG. 6 is a view similar to FIG. 5, illustrating a manner of locatingthe guide rod with respect to associated parts according to theinvention.

FIG. 7 is a side view mainly in section of a portion of an internalcombustion engine according to another embodiment of the presentinvention.

FIG. 8 is a perspective view of a flange and a guide rod similar tothose of FIG. 2 but constituting another embodiment of the invention,having an annular boss around the hole in each seat portion of theflange; and

FIG. 9 is a view similar to FIG. 6, showing a manner of mounting theflange shown in FIG. 8 on the cylinder head.

Similar numerals refer to similar parts throughout the several drawings.

Referring to FIG. 1, a rocker arm 1 is pivotally mounted on a rockershaft 2 and is capable of rocking motion around the axis of the shaft 2as actuated by a push rod 3 in a well known manner. In the shownembodiment of internal combustion engine, two generally identical valves4 and 4' are employed for each rocker arm. A bridge 5 whose ends are inthe form of arms 6 and 6, moves vertically on a guide rod 7 as guidedtherewith and actuated by rocker arm I, said guide rod 7 being locatedon a cylinder head 8 by a flange 9 as will be described more clearly. Avalve stem 10, adjustably connected with arm 6 by means of bolt 11threaded into said arm 6 and locked with nut 12 threaded to said bolt 11in such a manner as to provide freedom of adjustment, extends slidablyin the guide sleeve 13, which is press fitted in and passes through thecylinder head 8, so that, as the stem 10 is caused to reciprocate insaid sleeve 13 by the rocking action of the rocker arm 5 a valve disc 14seats on and unseats from the valve seat 15 to close and open a portformed in a cylinder 23. The guide sleeve 13 is provided at it top endwith a valve stem seal 35 in usual manner. Near a stem end 16, wherebolt 11 is threadedly engaged with the arm 6, there is provided on thestem a groove 17 for fittedly receiving a conical split key 18, aroundwhich is wedgedly secured an upper seat 19 for a valve spring 20. Thisspring 20 will urge the valve 4 toward its seated position.

In the cylinder head 8, an exhaust gas passage 21 and cooling waterpassage 22 are formed, as well-known techniques. The other valve 41,whose stem 10' is connected as above with the other arm 6, is associatedwith parts corresponding to those already mentioned of the valve 4, andsuch corresponding parts are referred to by like numerals with asuperscribed prime sign The valve mechanism arrangement thus fardescribed is conventional and comes under the techniques of prior arts.

According to an embodiment of the invention as shown in FIG. 1, theflange 9 is held down in place by shoulders 24 and 24' integrally formedof guide sleeves l3 and 13' respectively, each sleeve being press fittedinto the cylinder head 8 and, if desired, secured further to thecylinder head 8 by threading nut 25 to a threaded lower end portion 26of said sleeve protruding inwardly from the head 8, as shown in thedrawing, so that each shoulder 24 fastens the flange 9 to the head 8.

The bottom end of the guide rod 7 is rigidly fitted to and restrained inthe flange 9. Welding or press fit or threaded connection, or anycombination thereof, for example, can be adopted for securing rod 7 toflange 9; or the rod 7 and flange 9 may be formed integral, as desired,by machining a singlepiece stock.

FIGS. 2 through 6, inclusive, each show a guide device of the invention,consisting of the guide rod and the flange. In FIG. 2, the flange 9 hasits both ends recessed to present two seats 27 for the shoulders 24 torest on and is provided with a centrally positioned hole 28 in each seat27 for passing guide sleeve 13.

In FIG. 3 wherein respective parts are distinguished by adding asubscript letter a to each reference numeral, as necessary, the flange90 as a whole is in the shape of letter T, with an arm 29 extending fromits midsection in the plane of the flange. The arm 29 has a centrallypositioned hole 30 for passing a bolt 31, which is threaded into thecylinder head 8 to secure said flange direct to the head 8 as anadditional securing means.

In FIG. 4 wherein respective parts are distinguished by adding asubscript letter b to each reference numeral, as necessary, the flange9b as a whole is in the shape of a cross, with two arms 29b extendingfrom the midsection in opposite directions, each arm 29!) beingsimilarly provided with a centrally positioned hole 30b, as in FIG. 3,for the purpose of securing flange 9b additionally and direct tocylinder head 8 by means of bolts 31, as will be seen in the view insection of FIG. 5. It must be pointed out here that the bolts 31 areauxiliary members for the flanges of FIGS. 3 and 4.

In FIG. 6, the guide rod 7 protrudes downwardly from the flange 9, theprotruding portion being indicated at 32 and fittedly received by arecess 33 provided in cylinder head 8. The protrusion 32 and the recess33 in the head 8jointly serve as a means of accurately locating guiderod 7 in positional relationship to associated parts.

In FIG. 7, there is shown another embodiment of this invention, whereincorresponding parts are indicated by same reference numerals as inFIG. 1. The illustrated embodiment is substantially same as theembodiment shown in FIG. 1 except that the guide sleeve 13 has noshoulder 24. Therefore, the flange 9 of this device is fixed on thecylinder by only the action of the spring inserted between the seat 27on the flange 9 and upper seat 19. In another words, the bottom ends ofthe valve springs 20 are borne by the flange 9 to hold said flangeagainst the cylinder head 8 by its spring action. The flange 9 used inthis embodiment is shown in FIG. 8.

Referring to FIG. 8, which illustrates another modification of theflange for mounting the guide rod on the cylinder head, the flange 9 issimilar to that of FIG. 2, but the difference being that each seat 27with the hole 28 has an annular boss 34 forming an upward extension ofsaid hole 28 by its inside diameter, its outside diameter being sized tofit into and thereby restrict the bottom end of the valve spring 20 inlateral direction, such that the flange 9 is pressed down equally at itsrecessed seat ends against cylinder head 8.

The guide rod 7 shown in FIG. 8 may also protrude downwardly from theflange 9 as illustrated in FIG. 6. Such a device is shown in FIG. 9.

From the foregoing disclosure it will be readily seen that the flange,with which the guide rod is integrally or rigidly connected, is neitherwelded, threaded nor otherwise jointed to the cylinder head, so that thedrawback attendant on such a manner of jointing is eliminated and thatthe device can be easily removed to facilitate valve mechanismservicing. Furthermore, the force necessary for securing the flange tothe cylinder head is obtained not by additional parts but by slightlymodified regular members of the valve mechanism; and the flange andguide rod can be accurately located at the time of engine assembly asdetermined by the guide sleeves and/or the protruding end of the guiderod.

Thus, the guide devices according to the invention are easy to machineand fabricate and thereby improve engine production. I experimentallyused the disclosed guide devices in acfind that they are all effectivein accomtual engines only to plishing the stated object and alsoensuring the satisfactory and stable performance of the valves.

It is to be understood that this invention is not limited to the exactconstruction shown and described, but that various changes andmodification may be made without departing from the spirit and scope ofthis invention as defined by the appended claims.

What is claimed is:

l. A guide device for guiding movement of a multivalve actuating bridgein an internal combustion engine of the type having a cylinder head, apair of valves including stems slidably received through guide sleevesfitted into the cylinder head, and means for reciprocating said valvestems including a bridge being slidable on a guide rod and having a pairof arms for respectively sliding the valve stems through said guidesleeves: the guide device including a flange resting on the cylinderhead and having a pair of apertures respectively receiving said valveguide sleeves, said guide rod rigidly connected to said flange andprojecting upwardly therefrom, and releasable means including threads onthe lower ends of said guide sleeves and nuts respectively engaged onsaid threads.

2. A guide device for guiding movement of a multivalve actuating bridgein an internal combustion engine of the type having a cylinder head, apair of valves including stems slidably received through the cylinderhead, and means for reciprocating said valve stems including a bridgehaving a pair of arms for respectively sliding the stem; the guidedevice including a removable flange resting on the cylinder head andhaving a pair of apertures respectively receiving said valve stems, aguide rod rigidly connected to said flange and projecting upwardlytherefrom with said bridge being slidable on said guide rod, andremovable means engaged on said flange for maintaining said flange onsaid cylinder head against movement, said cylinder head having alocating recess on the top surface thereof, and said guide rodprojecting through said flange and received in said locating recess.

1. A guide device for guiding movement of a multivalve actuating bridgein an internal combustion engine of the type having a cylinder head, apair of valves including stems slidably received through guide sleevesfitted into the cylinder head, and means for reciprocating said valvestems including a bridge being slidable on a guide rod and having a pairof arms for respectively sliding the valve stems through said guidesleeves: the guide device including a flange resting on the cylinderhead and having a pair of apertures respectively receiving said valveguide sleeves, said guide rod rigidly connected to said flange andprojecting upwardly therefrom, and releasable means including threads onthe lower ends of said guide sleeves and nuts respectively engaged onsaid threads.
 2. A guide device for guiding movement of a multivalveactuating bridge in an internal combustion engine of the type having acylinder head, a pair of valves including stems slidably receivedthrough the cylinder head, and means for reciprocating said valve stemsincluding a bridge having a pair of arms for respectively sliding thestem; the guide device including a removable flange resting on thecylinder head and having a pair of apertures respectively receiving saidvalve stems, a guide rod rigidly connected to said flange and projectingupwardly therefrom with said bridge being slidable on said guide rod,and removable means engaged on said flange for maintaining said flangeon said cylinder head against movement, said cylinder head having alocating recess on the top surface thereof, and said guide rodprojecting through said flange and received in said locating recess.